Centrifugal casting apparatus.



E. P. BINFORD. OENTRIFUGAL OASTING APPARATUS.

APPLICATION FILED MAR. 23, 1908.

Patented Mar. 7, 1911.

.impression thus EDGAR P. BINFORD, OF CHICAGO, ILLINOIS.

CENTRIFUG-AL CASTING APPARATUS.

escaso.

Specification of Letters Patent.

Patenten nar. a, ieri..

Application filed March 23, 1908. Serial No. 422,772.

To all whom fit may concern:

Be it known that I, EDGAR P. BINFORD, a citizen of the lUnited States, residing at Chicago, in the countyof Cook and State of Illinois, have invented new and useful Improvements in Centrifugal Casting Apparatus, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

Thisv invention relates to improvements in centrifugal casting apparatus.

For filling cavities, and especially large cavities, an improved process, known as the inlay process, has recently come into use in dental work, which process comprises the taking of an impression of thevcavity in wax or similar moldable material fusing at a low temperature, employing the wax made as a pattern for casting a filling in gold or similar metal, and inserting this filling into the cavity in the tooth, the filling being then secured in place by some suitable method, as by the use of cement. rIhe best method thus far devised for casting the inlay is to place the wax impression in a flask l the impression orl pattern with investment material-this material being preferably a composition of plaster-of-Paris with other. materials. The wax pattern is then removed by the application of heat, the wax being boiled or burned out through a suitable sprue-hole. `The cavity formerly occupied by the wax pattern is then used as a castingmold, the cavity being filled with melted gold or other metal through the sprue-hole. Difficulty has heretofore been experienced in causing themelted metal to flow down throughfthe sprue-hole to the mold. The principal object of the present invention is to provide an improved process for casting inlay fillingsv in which this difhculty is overcome.

Another object is to provide suitable ap-y paratus for carrying out my improved process, this apparatus being of simple construction, efficient in action and reliable in its operation.

'Io these ends I provide a crucible, for the melting of the metal, in the flask itself, instead of melting the metal outside the flask and afterward introducing the same into the flask in its molten state-as has in some instances been done. VAfter the metal has been melted in the crucible in the flask it and fill the flask around.

is then injected through the sprue-hole into the mold by the application of centrifugal force.

In the accompanying drawings, Figure 1 illustrates an approved form of the apparatus which I employ in carrying out the process of casting inlay fillings according to my invention, and shows one of the steps of said process; Fig. 2 is a sectional view of the flask containing investment material and the wax pattern embedded therein, ready for burning or boiling out; Fig. 3 shows a modification of the device in which a flexible connection, consisting of a chain, is employed in place of the stiff rod of the form shown in Fig. 1. In this figure the flask containing'the mold and Crucible' is shown in section, the wax pattern having been removed; and Fig. 4 shows a further modified form of the apparatus. I

In the several figures of the drawings'. in which like reference numerals indicate the same parts throughout, 5 is 4the flask, conv sisting of a metallic,comparatively thin ring or tube, having its lower end flanged inwardly at 6 for a purpose hereinafter eX- plained. The impression 7, forming the pattern, is surrounded b v investment material 7a. The upper portion of the mass of investment material 7a is hollowed downwardly to form a crucible 8, in which ist'o be melted the gold or other metal of which the inlay filling is to be composed. A spruehole leads downward from the Crucible 8 to the space occupied by the pattern 7 Adapted to be attached to the flask 5 1s a removable bail 10, to which is secured one end of a bar, chain or the like 11, the other end of this member being swivelingly secured to the end 12 of a rod 13 having its opposite end provided with a handle 14 which may be grasped by the hand of the operator. The end of the rod 13 is preferably headed,l as shown in Fig. 1, and is grooved -at 15 to prevent the member 11 moving along the rod toward the hand of the operator.

In the use of this apparatus, and the employment of my improved method of casting, the flask 5, with the bail 10 and handle attached thereto, and containing the wax impression material 7 is placed upon a heating device, such as a Bunsen burner 16, and the Wax impression is burned out, a blow-pipe flame being used, if necessary, to hasten the burn- 7 embedded in the mvestment ing of the Wax. When the wax of the pattern 7 has wholly disappeared, the space formerly occupied thereby forms the mold 17 (see Fig. 3) in which the lilling is t be cast. A suitable quantity of gold 18 is placed in the crucible 8 and is there sub- )ected to heat from the Bunsen burner and also, if desired, to the heat from the blowpipe 19, until the gold melts.` When the gold has been reduced to a molten condition the flask is removed from thev burner by means of the rod 13, and a quick upward movement is given thereto, this sudden upward movement' causing the molten metal to flow, by reason of its inertia and consequent reaction, down the sprue-hole into the mold,

'The flask is now whirled preferably in a vertical plane,around the ro'd 13 by a suitable rotary movement imparted to the handle by the hand of the operator, the rod 11.

turning freely, by `reason of its swiveling connection, on the rod 13. The centrifugal force resulting from the circular movement of the flask about the rod 13 forces the molten metal into the'mold and holds it there until chilled and hardened. l

The part which connects the end-of the rod 12 withUthe bail 10 of the flask may consist either of a stili rod, as shown in Fig. 1,

or of a chain or similar flexible member, as `shown in Fig. 3. When the rod is employed it is preferably madev detachable from the bail 10, a. convenient form of separable connection between these parts being afforded by forming the end of the rod into a normally closed loop or ring, and bending the part 21 away from the body of the rod. A'similar form may be given the other end 22 of the rod 10, whereby the rod may be readily attached to or detached from the rod 13.

The inturned flange 6 around the lower edge of the flask prevents the mass of investment material from passing out of the flask under the influence of centrifugal force when the flask is whirled. A flask with/a closed bottom would be undesirable as the bottom would interfere with the operation of forming the mold of investment material around the pattern.

The bail 10 is made detachable to facilil tate the operation of forming the mold.

By moving the hooked ends'23 of the bail from the sides of the receptacle. In the use.

of ,this form of device the pattern may be removed as hereinbefore described, and, while still hot, the flask may beinsertedinto the receptacle 24. .'Ihe gold or other metal willnow be placed in the Crucible 8,v and the blow-pipe flame directed upon the same until it melts. T he receptacle 24, with the flask therein, will now be whirled around the handle'until' the metal cools, after which the flask will be removed and the casting taken therefrom' by dissolving out the investment material. a f

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is: i Y An apparatus for casting inlay fillings, comprising, in combination, a flask consisting` of a ring provided with an inwardly flanged lower edge, and having a removable bail, a rod having a handle upon one .of its ends for grasping the same, and connection between the oppositeend of said rod and said bail.

v In witness whereof, I have hereunto subscribed my name in the vpresence of two witnesses. v

EDGAR PBINF ORD.

Witnesses: 'I

M. S. FRRAR, C. L. HoPKiNs. 

